Transylvanian Principality: a vassal state of the Turks?

Transylvania used to be an integral part of the Kingdom of Hungary from the arrival of the Magyar tribes in the 9th century A.D. until the birth of the Transylvanian Principality in the 1570s.

Unlike some misconceptions, the Kingdom of Hungary didn’t cease to exist after the Battle of Mohács in 1526 and after the Habsburg attack in 1527, Transylvania didn’t become a mere vassal state of the Ottoman Empire.

Let us not forget, that we are talking about a sizeable land in Central Europe: the area of the Principality was almost twice larger than the size of modern-day Hungary’s. Even the present area of Székely-land, the home of the Hungarian Székelys is larger than modern Kosovo.

Now, I've summarized the lecture of a Hungarian historian, Balla Péter and we can learn more about this question: